Experimental Partnership-Experimental Research in Speculative Multithreading

EIA-0071924Gurindar S. Sohi威斯康星大学麦迪逊分校实验伙伴关系-投机多线程的实验研究投机线程不依赖于线程之间安全数据通信的保守保证。 相反，线程被推测性地分派，并且数据可以被推测性地通信。即通过假设它是正确的。 不正确的推测稍后被检测到，并且每当它们发生时，恢复被采取以确保正确性。 这种不太保守的方法来定义和调度线程发现并行的方式，保守的方法cannot.In这项研究中，主要研究人员将建立一个全面的，综合的实验基础设施，并使用它来进行调查的投机多线程处理器的设计相关的问题。沿着他们的研究生，主要研究人员将在推测性多线程处理器中进行实验研究。 现代并行处理系统将程序分解为并行执行的多个线程以提供高性能。 常规方法是指定并行线程，其中所有数据通信都经过仔细同步，以先验地保证正确性。 这种方法通常意味着必须使用保守的方法来提供必要的保证，从而限制并行性。 利用这一基础设施，研究人员将在三个主要领域进行实验研究。(1)推测线程识别和使用。 这将包括传统的“控制驱动”线程，重点将放在面向对象程序和商业工作负载提供的新机会上。 它还将包括“数据驱动”线程，一种新形式的推测线程，它有望为从传统程序中提取并行性提供新的机会。(2)软件/硬件交互。 线程的动态程序特性对于管理它们的标识、调度和数据通信可能是至关重要的。 在许多大型的基于网络的应用程序中，动态链接也将被完成，这将极大地限制静态编译器的视野。 研究人员将研究新的方法，通过这种方法，硬件和软件可以相互作用，编译和执行推测性的多线程程序。 这将包括允许有效通信的结构特征以及使用动态分析和重新编译技术。(3)混合“混合线程”处理。 在未来的处理器和系统中，几种线程类型可能会共存。 这包括作为拟议研究的中心焦点的推测性线索。 它还包括传统的非推测线程，这些线程可以B软件编译工具和/或硬件显式编程或隐式提取。 因此，将互补线程类型集成到内聚的“混合线程”处理模型中的处理器和系统将被开发和研究。

EIA-0071924Gurindar S. SohiUniversity of Wisconsin-MadisonExperimental Partnership-Experimental Research in Speculative MultithreadingSpeculative threads do not depend on conservative guarantees of safe data communications among threads. Rather, threads are dispatched speculatively, and data can be communicated speculatively. i.e. by assuming that it is correct. Incorrect speculations are detected later, and whenever they occur, recovery is under taken to assure correctness. This less conservative approach to defining and dispatching threads find parallelism in ways that conservative methods cannot.In this research, the principal investigators will build a comprehensive, integrated experimental infrastructure and use it to carry out an investigation of issues related to the design of speculative multithreaded processors. Along with their graduate students the principal investigators will conduct experimental research in speculative multithreaded processors. Modern parallel processing systems decompose a program into multiple threads that execute in parallel to provide high performance. The convention method is to specify parallel threads where all communication of data is carefully synchronized to guarantee correctness a priori. This approach often means that a conservative approach must be used to provide the necessary guarantees, there by constraining parallelism. Using this infrastructure, the investigators will conduct experimental research in three primary areas.(1) Speculative Thread Identification and Usage. This will include conventional "control-driven" threads where the focus will be on new opportunities provided by object-oriented programs and commercial workloads. It will also include "data-driven" threads, a new form of speculative thread, which promises to open new opportunities for extracting parallelism from conventional programs.(2) Software/Hardware Interaction. Dynamic program characteristics of threads are likely to be criticalfor managing their identification, scheduling, and data communication. Dynamic linking will be done as well, in many large network-based applications and will very much limit the static compiler's view. The investigators will research new methods by which hardware and software can interact to compile and execute speculative multithreaded programs. This will include architecture features to permit efficient communication and the use of dynamic profiling and re-compilation techniques.(3) Hybrid "Mixed Thread" Processing. In future processors and systems, it is likely that several thread types will co-exist. This includes the speculative threads that are the central focus of the proposed research. It also includes the traditional non-speculative threads, which may be either explicitly programmed or implicitly extracted b software compilation tools and/or hardware. Consequently, processors and systems that integrate the complementary thread types into a cohesive "mixed thread" processing model will be developed and studied.